/Engine/Source/Runtime/ApplicationCore/Public/GenericPlatform/GenericApplication.h
Constructor. Events are immutable once constructed.
FModifierKeysState ( const bool bInIsLeftShiftDown, const bool bInIsRightShiftDown, const bool bInIsLeftControlDown, const bool bInIsRightControlDown, const bool bInIsLeftAltDown, const bool bInIsRightAltDown, const bool bInIsLeftCommandDown, const bool bInIsRightCommandDown, const bool bInAreCapsLocked )